Java计算器程序代码

用NetBeans创建窗体，再通过编写代码实现按钮的功能。步骤如下，因为是初学者，所以只实现了基本功能。

1)先创建计算机窗体



2）为各个按钮添加事件

private void jButton1MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

//调用setNum方法

setNum("1");

}

private void jButton2MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("2");

}

private void jButton3MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("3");

}

private void jButton4MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("4");

}

private void jButton5MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("5");

}

private void jButton6MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("6");

}

private void jButton7MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("7");

}

private void jButton8MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("8");

}

private void jButton9MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("9");

}

private void jButton18MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

//调用setYSF方法

setYSF("+");

}

private void jButton19MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setYSF("*");

}

private void jButton12MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setYSF("/");

}

private void jButton11MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setYSF("-");

}

private void jButton15MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code her

setNum(".");

}

private void jButton13MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

setNum("0");

}

3）实现各个按钮的功能

//等于按钮的功能实现

private void dengyuMouseReleased(java.awt.event.MouseEvent evt) {

ScriptEngineManager manager = new ScriptEngineManager();

ScriptEngine se = manager.getEngineByName("js");

Double result = null;

try {

result = (Double) se.eval("(" + jTextField1.getText() + ")*1.0");

} catch (ScriptException ex) {

Logger.getLogger(JFrame.class.getName()).log(Level.SEVERE, null, ex);

jTextField1.setText("输入错误，按c重新输入");

}

jTextField1.setText(result.toString());

}

//退格按钮的功能实现

private void tuigeMouseReleased(java.awt.event.MouseEvent evt) {

//得到jTextField1中的文本

String strText = jTextField1.getText();

//判断文本的长度是否大于1

if(strText.length() > 1){

//如果大于1，删除最后一位

StringBuffer strBuf = new StringBuffer(strText);

strBuf.deleteCharAt(strBuf.length() - 1);

//把文本放回jTextField1

jTextField1.setText(strBuf.toString());

}else{

jTextField1.setText("0");

}

}

private void jButton16MouseReleased(java.awt.event.MouseEvent evt) {

// TODO add your handling code here:

jTextField1.setText("0");

}

//对数字进行处理

public void setNum(String str){

String strText = jTextField1.getText();、

//如果文本为0，那么显示按键的字符

if(strText.equals("0")){

jTextField1.setText(str);

}else{

//如果不是，就追加

StringBuffer strBuf = new StringBuffer(strText);

strBuf.append(str);

jTextField1.setText(strBuf.toString());

}

}

//对运算符进行处理

public void setYSF(String str){

String strText = jTextField1.getText();

//如果最后一位为运算符，那么换为按键字符

int lastRight = strText.length()-1;

char ch = strText.charAt(lastRight);

if(ch=='+'||ch=='-'||ch=='*'||ch=='/'){

String strResult = strText.substring(0, lastRight)+str;

jTextField1.setText(strResult);

//如果不是，那么可以继续加入按键字符

}else{

jTextField1.setText(strText+str);

}

}

4）运行文件



结果显示